Oil burner



April 11,- 1944.

H. c. Rol-m ETAL 2,346,398'

OIL BURNER Filed July 1v, 1940 2 swans-'sheet 2 r 9i Cttornegs PatentedApr. 1l, 1944 n assignors to General Motors Corporation,

' Detroit, Micln, a corporation ot Delaware Application July 17, 1940,Serial No. 343,033

's claims. (ci. rose-42) This invention relates generally to oil burnersand more particularly to improvements in the construction of burners ofthey gun or pressure atomizing type.

Oil burners of this type are generally characterized by the provision ofa rotary air fan and a fuel oil pump driven by a common electric motor.An oil filter is generally provided between the source of oil and theintake to the oil pump and oil under pressure from the pump outlet issupplied through the intermediary of a pressure regulating valvearrangement to an atomizing nozzle adjacent or within an air duct fromthe fan.

One object of the present invention is to provide a unit assembly whichincludes one of the endbearings for the motor shaft, an oil pumpassembly, the pressure regulating valves and an oil filter in which allof such parts are readily accessible for examination, repair orreplacement.

.4i further object of the invention is the construction of the oil pumptogether with a sealing means for the rotating shaft of the pump as aunit assembly which may be readily installed and removed as a unitwithout disturbing other parts ci the burner.

.e still further object lis the provision of the oii filter in the formof a readily removably cylinder or tube around the oil pump unit wherebyall Figs. 6, 7 and s are elevations-.of the several parts of the oilpump to be described hereinafter.

in detail.

Referring ilrst to Fig. 1- for a general showing of the complete oilburner, the rotary fan or blower housing 2 with the integral burner tube4 Ais supported on pedestals 6. Thevelectric motor .with a shaftcarrying the fan or blower on one end and connected to drive the oilpump at the proceeding now to a detailed description of the oil tothepump intake passes through the filter which may be readily removed forinspection and replacement when desired.

With reference to the foregoing objects, the

construction and arrangement of parts is such as to not only simplifythe same and provide for ease ci' manufacture and accessibility forinspection and service but also to eliminate projecting parts andprovide the minimumo external connections to thereby improve theappearance of the complete burner. y

Other objects and features of the invention to'- gether with theadvantages thereof wili be apparent from. or specifically pointed out inthe follow- A ing description and accompanying drawings of oneembodiment of the invention in which:

Fig. 1 is a side elevation, with parts broken away, of acompleteburner.- l l w Fig. 2 is an enlarged vertical section, takenpresent invention and referring particularly to .Figa 2 and 5, Aa casing24 is adapted to be secured to the motor frame 8 in any desired manner.This casing 2s constitutes an end housing for the motor and is providedwith the bearing 2t for one end of the motor shaft 23. The motor shaft23 is provided with an oil slinger groove and oil slinger ring 32 onopposite sides of the bearing 26 and lubrication is provided by the oilwick 3e in chamber 36 to which oil may be supplied through oil cap 38and passage t6.

The casing 2t ls formed with a relatively large chamber te having an endopening adapted lto be closed by the cap t8 secured to the casing as byscrews Eil with a sealing gasket 5E to form a housing for the oil pumpand filter unit. This chamber @l also constitutes a suction chamber forthe pump and communicates at one side with the oil supply pipe it. Anupwardly extending baille.

oribarrier wall lit is provided in chamber It adjacent the connection tooil pipe i4 to permit the oil inlet to be brought in at the side of thecasing substantially online 2-2 of Fig. 1, of that portion of the burnerembodying the present invention. Fig. 3 is a fragmentary section to showcertain passages taken substantially on line #-3 of Fig. 5.

Fig. 4 is a fragmentary section taken substantially on line 4-4 of Fig.5.

Fig. 5 is a transverse section taken substantially on line B-l of Fig.2. v

and. trap a certain amount of oil in the chamber up to the level of theupper edge of the baille or barrier wall to thereby keep the pump andsurrounding iilter covered with oil.

Theoil pump body comprises the circular plate 56 which is securedbetween end plates 58 and 80 as a unit ley-screws 62 in thediametrically opposite holes 64, and to accurately align the platesaxially when assembling the unit in the manner to be hereinafter'described. dowels 68 are also provided in the diametrically oppositeholes 68.

'Ihe oil pump per se is of conventional type comprising the pinion 10.crescent 12 and internal gear 14. The internal gear 14 is journaledwithin the pump body plate 56 and adapted to be rotated by the pinion'I0 having diametrically opposite slots 16 to receive the ends of theldrive pin 18 passing through th'e pumpshaft 80.

Before proceeding to a further description of the pump unit it isdesired to note that certain parts mentioned above have been shown inFig.

The oil pump with the'several plates and the sealing means is assembledtogether as a complete unit which may be readily installed or re- 6 asif secured to or forming a part of the plate Y 60, but it should beunderstood that the pump shaft 80 extends through and rotates relativeto f this plate, the crescent 12 may be separately formed and merelypositioned on the plate 60 by dowels, and the dowels 66 are adapted tofit within holes in plates 60 similar to the holes 68 in plates 56 and58. With further reference to the assembly of plates 56, 58y and 60-withthe pump parts it has been found desirable to first assemble the plateswith a shaft and a set of slightly oversize gears and th'en drill thedowel holes 68 so that when the oversize gears are removed and the pumpunit is assembled with gears of the correct dimensions, the parts willoperate smoothly Without binding.

The face of the outer or front plate 58 which is adapted to contact withthe plate 56. is formed with an oil intake groove or channel 82extending from the periphery thereof to a recess 84 adjacent the intakearea of the pump gears and the inner or rear plate 60 is formed on theface opposed tothe plate 56 with a recess 86 adjacent the discharge area"of the pump gears which communicate with an oil outlet passage 88 ex- Ytending through plate 60 to the opposite face thereof. 'I'he plate 58 isformed with a further recess 90 which Iis opposite the recess 86 inplate 60 andthe plate 60 is formed with a further recess 92 which isopposite the recess 84 in plate 58, such recesses 80 and 02 serving'toequalize the pressure on the side faces of the pump gears and thusprevent undue side pressure on the gears.

The rear face of the plate 60 is provided with a cylindrical recess toform a chamber 94 to house the pump shaft sealing means. The pump shaft80 is formed witha shoulder 96 and abutting this shoulder is a hardenedsealing ring 98 which may be held in position by a ring |00 on theshaft. The ring |00 is preferably made of such material as Duprene,neoprene, or similar rubber substitutes or such material as will sealthe joint between th'e shaft 80 and the sealing ring 98. The rings 98and |00 rotate with shaft 80 and the ring 98 is adapted to be engaged bya sealing ring |02 which is secured to av exible diaphragm |04 by meansof a member |06 which is spun over the inner edge yoi? ring I 02. Theouter edge ofthe diaphragm |04 is secured against a shoulder withinl therecess in plate 60 by a screwthreaded clamp ring |06 with a slightlyiiared wash'er and a flat washer interposed between the clamp ring anddiaphragm `as shown.

The engaging surfaces ofthe seal rings 98 and -with the plates 56, 58and 60.

moved. As has been heretofore Adescribed thepump parts are assembledwith the three plates `56, 58 and 60 secured together by screws 62.- As

shown in Fig. 2 the outer end of the pump shaft 80 is extended beyondthe plate 58 and held from inward movement by the cotter key,| I4 andwashers II6, whereas outward movement of the shaft 80 is resisted byspring ||0 and limited by en. gagement of member |06 with the adjacentportion of ,plate 60.

The inner end of the pump shaft 80 and the adjacent end of the motorshaft 28 are provided with a suitable coupling I8 such as acooperatingtongue and groove and the unit assembly of the pump andsealing means may be secured t the .casing-24 by the spaced screws |20,shown as flve in number, extending through aligned holes |22 in plates56, 58 and 60, with a sealing gasket |24 clamped between casing 24 andplate 60.

A filter |26 is positioned in casing 24 within the chamber 46 and may bemade of any suitable,l

material such as cotton yarn wound on ascreen wire supporting cylinderY|26 which is concentric This filter is adapted to be removably clampedagainst. the casing 24 by the end cap 48 which is formed with thecircular angular face |30 which embeds itself in one end of the'fllter|26 as shown in Fig. 2

and compresses the lter against the casing at its opposite end.

The casing 24 is formed with'a recess adjacent the inner end of thevpump unit to provide a space |32 to receive the inner end of the pumpshaft 80 and the coupling ||8 to the motor shaft 28 and a passage |34extends through the .casing 24 from this space |32 to drain any o ilwhich may leak into the space |32 to a point outside of casing 24 andindicate that the sealing means is not functioning properly. The upperside of casing 24 is also provided with an opening into the chamber 46which may be normally closed by a plug |36 to provide for priming thepump or for attaching a vacuum. gage to test the pump suction.

As has been heretofore described, the plate is provided with the oiloutlet or discharge passage 88 extending to the inner face thereof. Anopening through the gasket |24 is adapted to be aligned with thispassage and passage |38 in the casing 24 which communicates withintersecting passages |40 and |42 drilled in the casing 24 which areclosed at their junction with the outside of the casing by plugs |44 and|46, respectively.

Such passages supply the oil from the pump to a pressure regulatorchamber |48 in the casini;v

`|54 may be readily adjusted by means of the screw l|58 engaging pin |56and the threaded opening for this screw may be normally closed by |02are highly finished and the ring |02 is maining up of any pressurewithin the chamber 94, a

passage II2 is provided through the plate 60 to .connect the chamber 94to the suction chamber 46.

the' removable cap |60.

Axially aligned with the piston |50 is a threaded cap |62 to which issecured a valve guide and, cage |64. The cap |62 is provided with a port|66 communicating with a connection to the oil-delivery pipe I6 andwithin the cage |64 are two oppositely directed needle valves |68 and|10 with a relatively light spring |12 urging both valves toward thepiston |50 which is provided with a port |14 communicating with the oilbytion of a pressure sage to determine the oil prespass chamber |16 incasing 24. As will be apparent, the valve |68 is adapted to control port|66 and the valve is adapted to control port |14 with a bleed groove |18machined in the conical face of valve-|10 for a purpose to be hereafterset forth.

Considering now the operation of the pressure regulating valve arrangeddescribed above, it will be seen that when the pump is not operating,the

spring |64 holds the pistonJS against valve |10 sure in this chamber orto vent any air from the system.

As will be apparent from the foregoing description. the-oil pump andseal assembly is readily detachable as a unit-and may be separatelytested or quickly removed and a new unit substituted with only a shortinterruption of burner operation. The filter surrounds the pump unit andis of simple structure and readily removable for cleaning orreplacement, and all oil including that recirculated through the pumpmust pass through the filter to enter the pump intake channel 82.

l All of the principal parts are contained within the to supply oil tothe burner nozzle. During a part l of the travel of the piston the valveIl@ remains seated in port ile, but when movement of this valve isstopped by engagement of a shoulder thereon with the end of the cage IM,the continued movement of the piston opens the port |14 to permit excessoil to flow into the by-pass chamber |18. p

The pressure .regulating valve arrangement is therefore such that oil isonly delivered .through port |66 to the burner nozzle when the pressurethereof is of the desired value or range of values and whenever thepressure in chamber |48 exceeds the desired value, the oil will beby-passed through port |14 into the chamber |16. When the pressure dropsbelow the desired value due to stopping the oil pump or for any otherreason,

' the piston |50 will move to first close by-pass port |14 and then moveboth values to close the burner port |66. `'I'he bleed groove |18 invalue |1Q permits oil leakage through the port |16 to reduce thepressure in chamber |48 and permit quick and complete closing of theburner port |66 when the pump is stopped. It will be apparent that thepressure of th oil to the burner nozzle may be readily adjusted by thespring tension adjusting screw |58 and the extent of opening of port |14and amount of oil entering the by-pass chamber |16 will be governed bythe oil pressure and the settingoi.' the spring les. 'I'he oil which islay-passed to chamber |16 may be either recirculated directly to thepump intake chamber or returnedto the supply As shown in Fig. 3, alignedthreaded openings are provided in casing 26 from the luy-pass chamber|16 to the intake chamber. 48 and to the outside of casing 24. 'I'heinner opening |86 into the chamber 46 is slightly smaller than the outervopening |82 which is shown as closed .by a plug |84 whereby theoil.from the by-pass chamber` |16 will be returned directly i to thepump intake or suction chamber 48. If

it is desired in any installation to return the oil to the supply tank,it is merely necessary toremove the plug |64, place a plug in the inneropening. IIB and connect an oil return pipe with the outer opening |82.

As shown in Fig. 4 a passage |66 is provided in the lower 4part ofcasing 24 and normally closed by a plug |88 to permit the chamber 46 tobe drained and cleaned. An opening through the casing into pressureregulator chamber |48 may als be provided as shown in Fig. 2 andnormally closed by a plug i to permit the connec- I5 single casing 24with the advantage that the parts are maintained in their properrelation and the external appearance is improved as will be particularlyapparent from the showing in Fig. 1.

It will be apparent that many changes and modifications may be made inthe detailed conl struction and arrangement of parts within the scope ofthe present invention and that many advantages of the several novelfeatures thereof in addition to those specifically mentioned here-l inwill be obvious to those skilled in the art. 4

We claim: l. In an oil burner, -a fuelsupply unit inciud-. ing anelectric motor having a motor frame and a. motor shaft, a unitaryhousing secured to said motor frame and provided with a portion forminga closure for an end of said motor and a bearing for one end of saidmotor shaft.y a pump chamber in said housing, a fuel pump unit in saidchamber including pumping elements, a pump shaft. and sealing means forsaid pump shaft, a`

coupling between said motor shaft and pump shaft, a recess in saidhousing between said motor shaft bearing and said pump unit to receivesaid coupling, and a drain passage extending from said recess throughsaid housing to the outer side of said housing whereby said drain willserve to indicate any leakage of oil .pastsaid sealing means into saidcoupling recess.

2. In an oil burner, ahousing provided with' a pump chamber having inlet,and outlet passages,

a fuel pump unit including intermediate and end plates, pumping elementsin said intermediate plate, an intake passage formed between saidintermediate plate and` one of said end plates, an

outlet passage extending through said other end plate adapted tocommunicate with said pump 'chamber outlet passage, a pump shaftjournaled in said end plates, a. sealing means for said pump shaftconnected to one of said end plates, means to secure said platestogether whereby said pump unit comprises a self-contained unitincorporating the said pumping elements, pump shaft and pump shaftsealing means, and means for detachably securing said pump unit to saidhousing within said pump chamber.

3, In an oil burner, a housing provided with a pump chamber having inletand outlet passages, a. fuel pump unit including intermediate and endplates, pumping elements in said intermediate plate, an intake passageformed between said intermediate plate and one of said end plates,

an outlet passage extending through said other end plate adapted tocommunicate with said with means forcing the same into engagement' withsaid rotatable sealing ring, means to secure said plates togetherwhereby said pump unit com prises a self -contained unit incorporatingthe said pumping elements, pump shaft and pump shaft sealing means, andmeans for detachably securing said pump unit to said housing within saidpump chamber.

14. In an oil burner, a fuel supply unit including a housing-formed witha pump chamber having an end wall adapted to receive the end of a motorshaft, a fuel pump unit adapted to be removably mounted in said chamber,said unit including a pump shaft, pumping elements and a sealing meansfor said pump shaft, means to detachably secure said shaft, pumpingelements and shaft sealing means together as a self-contained unit, andmeans to detachably secure said unit to the said end wall within thepump chamber.

5. In an oil burner, a fuel supply unit including a' housing formed withapump chamber having an end wallv and a detachable cover for saidchamber, a drive shaft extending4 through-said end wall, a. pump unitincluding a pump shaft,

pumping elements and a sealing means for said pump shaft adjacent oneend thereof, means to detachably secure said shaft, pumping elements andshaft sealing means together, and means to detachably secure said pumpunit to saidend wall with said pump shaft in disconnectible engagelmentwith said drive shaft so that said pump 3 shaft, pumping elements andshaft sealing means may be installed or removed as a self-contained unitwhen said cover is removed from said housing.

6. In an oil burner, a housing provided with a pump chamber having aninlet opening and an end wall having an outlet passage, a drive shaftextending through said end wall into said chamber, a fuel pump unitadapted to be removably mounted within said chamber, said unit includinga plurality of plates, pumping elements and a pump shaft, said plateshousing said pumping said elements from said chamber and an outletpassage adapted to communicate with said outlet passage in said endwall, detachable means for securing said plates and pumping elementstogether, means for detachably mounting .said pump,v shaft in saidplates including a sealing means for said pump shaft adjacent one endthereof adapted to limit movement of said shaft in one diretcion andmeans adjacent the other end of said shaft adapted to limit movementthereof in the opposite direction, and means for detachably securingsaid pump unit to said end wall with said pump shaft in dsconnectibleen-- gagement with said drive shaft so that said pump unit together withsaid pump shaft sealing means may vbe installed or removed withoutdisturbing the drive shaft or the inlet and outlet of said pump chamber.4 HENRY C. ROHR.`

PETER. R. CONTANT.

